Atmospheric processes in the Central Arctic during MOSAiC

The atmosphere plays a central role in the Arctic climate system and its recent changes. Enhanced Arctic atmospheric warming over the past decades is linked with many key processes, including variability in large-scale circulation patterns, changes in fluxes of heat, sea-ice decline, impacts on the ecosystem, and many more. It is this collection of interdependent processes, and their recent changes, that has motivated the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC, 2019-2020) expedition. Based on the Polarstern icebreaker, an international and interdisciplinary team of scientists conducted an intensive, year-long scientific exploration of the Central Arctic climate system while drifting with the sea ice. This presentation highlights the atmospheric components of this scientific expedition. These include the most comprehensive set of field observations to ever be made of the Central Arctic atmosphere, spanning from the stratosphere to the surface. Specific research activities examine atmospheric structure, winds, clouds, precipitation, aerosols, and surface fluxes of heat, momentum, gases, and moisture. Complementing these observational aspects are numerous modeling activities, including observation-based model assessment, model development, and regional process studies, among others. Finally, key links between the atmosphere and the sea ice, snow, and ocean through a variety of physical, chemical, and biological processes are discussed.